A very large number of aluminum cans for beverages such as beer and soft drinks are produced in the United States--as well as in Canada, Australia, France, Germany, Argentina, Brazil, and elsewhere--each year. It has been estimated that the output of aluminum beverage cans in this country amounts to more than one hundred billion cans per year.
Aluminum beverage cans are today manufactured by the well known process known as two-piece drawing and wall ironing. As a part of this process, the bottom wall of the can and the bottom portion of the cylindrical side wall are made thicker than the upper portion of the side wall. The top wall or lid of the can is also thicker than the side wall, as well as being constructed from a different aluminum alloy than the other walls of the body are.
The top wall or lid of the can customarily has a substantially smaller diameter (typically about 2.1 inches or 53 mm.) than the inside diameter of the main body portion of the can (typically about 2.6 inches or 66 mm.). Even so, the lid constitutes about one-fourth the total weight of the can.